Infusion apparatus



July 19, 1938. rH. GoLDsTElN y INFUSION APPARATUS Filed Jan. 2, 1936 Patented July 19, 1938 UNITED STATES PATENT OFFICE INFUSION APPARATUS 6 Claims.

This invention relates to infusion apparatus for injecting uids into the human body and more particularly to a heat control device for maintaining such fluids at the proper temperature.

This invention is an improvement over that disclosed in my Patent 1,995,302 dated Mar. 26, 1935 for Adjustable heating infusion apparatus.

In the apparatus ydescribed in said patent, it is necessary to sterilize the entire apparatus before each use. Such repeated sterilization and use tends to cause scales or other impurities to form in the rubber tube which renders the same unsuited for use for infusion purposes and also materially shortens the useful life of the. apparatus due to deterioration of the rubber.

An object of the present invention is to eliminate the necessity for sterilizing the entire apparatus.

Another object is to provide a replaceable ster- .20 ile inner tube which may be threaded through the heating apparatus.

Another object is to provide means for preventing the inside of the tube from being unsterilized due to its passage through the non-sterile heating apparatus.

Another object is to provide a cheap, simple and dependable device of the above character.

Various other objects an-d advantages will be apparent as the nature of the invention is more fully disclosed.

A feature of the invention consists in lthe provision of a heating element made in tubular form into which may be threaded, the rubber tube to be used for the injection of fluid into the body.

A further feature consists in the provision of means for maintaining the inner tube in a sterile condition while it is being threaded through the heating element.

In one embodiment, the heating element is to formed as a helix wound upon a tube of insulating material such as a rubber tube and covered by a suitable heat and electrical insulation such as asbestos and rubber. The inner tube is adapted to be threaded through the tube supporting the helix. For this purpose the inner tube is provided with a cap which is screwed onto the end thereof and which seals the end for maintaining the inside of the tube sterile. The cap is provided with means for receiving a string or the like which 515 is passed through the heating element, secured to the cap and used to pull the cap and associated tube into position within the heating element.

The cap may then be removed and the tube connected to the fluid receptacle and to the injector needle in any well known manner.

(Cl. 12S-227) Although the novel features which are believed to be characteristic of this invention will be more particularly pointed out in the claims appended hereto, the invention itself, as to its objects and advantages and the manner of its operation, may be better understood by referring to the following description taken in connection with the accompanying drawing in which one embodiment of the invention is set forth for purposes of illustration.

In the drawing:

Fig. 1 is a broken elevation of the heating element and inner tube in assembled position.

Fig. 2 is a section taken on the line 2-2 of Fig. 1L

Fig. 3 is an elevation of the heating element and tube. partly broken away to show a step in the threading operation.

Fig. 4 is a broken elevation of the inner tube and Fig. 5 is an enlarged detail View showing the cap by which the inner tube is closed and threaded through the heating element.

In the following description and in the claims certain specific terms are used for convenience in referring to various details of the invention. These terms, however, are to be given as broad an interpretation as the state of the art will permit.

Referring to the drawing more in detail, the invention is shown as applied to a flask I3 of usual construction for containing the fluid to be injected. The flask IU communicates with a short piece of rubber tubing I I provided with a pinchcock I2 by which the rate of flow may be controlled and connected to a conventional sight or Murphy glass I3 in which the rate of flow can be observed.

The Murphy glass I3 is connected to a rubber inner tube I4 which passes through the heating apparatus to be described and is attached to a nipple I5. For this purpose the nipple I5 is provided with a tapered hub I6 having a recess I I in which the end I8 of the tube I4 is held as by a band I9.

The nipple I5 is also provided with a tapered hub 20 which may be frictionally attached in a tapered bore 2| of a casing 22. The casing 22 may be formed of metal or glass and may have a chamber 23 surrounding a thermometer Well 24. The end of the casing 22 opposite the bore 2I may have a tapered hub 25 fitting in the bore of an infusion needle 26. The hubs 2D and 25 are preferably identical so that the casing 22 may be omitted when desired and the hub 2@ of the nipple I5 attached directly to the. infusion needle 26.

The heating apparatus in which the tube I4 is held comprises a supporting tube 35 of suitable material, such as rubber, upon which a heating coil 36 is wound in the form of a helix, preferably with the folds closer together at the top end than at the bottom endso as to facilitate the control of the temperature of the fluid passing therethrough and to minimize the effect of variations in the rate of flow on the temperature. The heating coil 36 is covered by a layer 3'I of heat insulating material such as asbestos which may in turn be covered by a rubber casing 38. The various parts of the heating element above described will be sealed together for completely enclosing the heating coil and preventing damage thereto due to contact with water.

The upper end of the heating apparatus may carry a protective casing 39 of rigid material such as Bakelite which may be made into sections 46 and 4I clamped by rings 42 to the rubber casing 36. The ends of the heating coil 36 are secured under this protective casing 39 and are connected to a socket 43 formed therein, which is adapted to be connected to a suitable source of current, not shown. Obviously, a thermostat may be used in conjunction with the heating coil, if desired, such, for example, as the thermostat disclosed in my above mentioned patent.

It is to be understood that the inner tube I4 is entirely separate from the supporting tube 35 and may be readily removed from the heating assembly. In order to facilitate the threading of a new inner tube I4 through the heating assembly, the nipple I is provided with an external thread 44 which is adapted to be engaged by cooperating threads 45 formed in a cap 45 which may be screwed onto the nipple for closing the same and sealing the interior of the tube I4 so as to prevent contamination of the inside thereof due to passage through the non-sterile heating assembly. The cap 46 is provided with an eX- tension 4i' adapted to pass over and protect the end of the tube I4 so as to provide a substantial sterile area near the nipple I5.

The cap- 46 may be provided with suitable means to receive a string 48 by which it may be threaded through the heating assembly. In the embodiment shown, a hole 49 is tapped in the cap 46 and is adapted to engage a plug 56 having an eye 5I in which the string 48 may be secured. It is obvious, however, that other means for securing the string 48 to the cap 46 may be `used without departing from the spirit of the present invention.

In using the present device, it is contemplated that the tube I4 will be used only once, after which it will be discarded or used for other purposes which, do not require sterility. Consequently, whenever the device is to be used for the injection of the iiuids into the body, a sterile tube I4 is obtained. This tube may be secured to the Murphy glass I3 in any Well known manner and may be sterilized if it is not already in a sterile condition. It is: sealed by screwing the cap 46 over the nipplev I5 and in this condition can be threaded through the heating assembly without danger of unsterilizing the inside of the tube. The heating assembly is inverted, as shown in Fig. 3, and the string 48 with the plug 59, is dropped therethrough. The plug 50 is then screwed into the tapped hole 49 in the cap 4E, after which the cap and the tube I4 are pulled through the heating assembly. The cap 46 may then be removed and the'nipple I5 secured to the casing 22 or to the needle 26.

The inner tube I4 remains sterile due to the seal effected by the cap 46. Furthermore, the extension 4l of the cap protects the end of the tube I4 and the nipple I5, thereby providing sterile areas near the point of attachment to the infusion needle. The nipple I5 is so formed that the end 48 of the tube I4 slides within the extension 4l and is concealed thereby. The end of the extension 4l may be further enclosed by a protective material, such as collodion or cellophane or other readily removable material, if desired, to ensure sterility thereof and to prevent the same from unsterilizing the nipple when the cap is removed.

Obviously, other means for threading the tube I4 through the heating assembly may be substituted for the string 48, if desired, and any confvenient means may be provided for attaching the same to the cap 46. A preferred form has been shown merely as an illustration.

1t is to be noted that the heating element may be constructed with great durability as it is not necessary to discard the same when the inner tube becomes unfit for use. Furthermore, the life of the heating element isv greatly increased due to the fact that the heating element and the associated supporting means are not repeatedly sterilized. The patient is assured of a sterile tube with the least possible expense and inconvenience and at the same time may obtain the benet of the heating apparatus described above. Since the inner tubes I4 cost only a few cents, they may be thrown away or discarded after being used only once, thereby eliminating any danger that scales or other impurities may be present therein.

It is obvious that the specific construction of the heating assembly may be varied as desired. In certain instances the heating coil may, for example, be imbedded in a layer of insulating material, in which case the supporting tube may be omitted. In any event, the supporting tube may be formed of thin material so as to facilitate the transfer of heat therethrough.

Although a specific embodiment of the invention has been set forth for purposes of illustration, it is to be understood that the invention is only to be limited in accordance with the scope of the following claims when interpreted in view of the prior art.

What I claim is:

1. In an infusion apparatus, in combination, a heating coil, a iiexible tube carrying said coil, a second flexible tube adapted to be inserted within said first tube, said second tube having a nipple secured in one end thereof and provided with a detachable cap adapted to seal said second tube and to be attached to a line for pulling the second tube through said first tube.

2. In an infusion apparatus, in combination, a heating coil, a flexible tube carrying said coil, a second flexible tube adapted to be inserted within said first tube, said second tube having a nipple secured in one end thereof, a cap threaded onto said nipple for closing the same and means associated with said cap to receive a line for pulling the second tube through said first tube.

3. In combination, a flexible tube, a nipple secured in one end thereof, a cap sealing said nipple and means associated with said cap to receive a line for pulling the tube into a desired position.

4. In combination, a flexible tube, a nipple secured in one end thereof, a cap threaded onto and sealing said nipple, and a plug, having an eye to receive a line, threaded into said cap.

5. In an infusion apparatus, in combination, a heating coil, a exible tube carrying said coil, a second flexible tube adapted to be inserted Within said rst tube, said second tube having a nipple secured in one end thereof, a cap threaded onto said nipple for closing the same and extending over the adjacent end of said tube to protect the same.

6. In an infusion apparatus, in combination, a

heating unit comprising a flexible tubular support, an electrical heating coil mounted thereon, a layer of heat insulating material suirounding said heating coil to heat insulate the outside thereof, and a second exible tube extending through and removably supported in said unit in heat transfer relationship with said coil and adapted to supply fluid to an infusion needle.

HAROLD GOLDSTEIN. 

